There are many positions in the club, but thus far there are only two members, Calvin and Hobbes. During meetings, they spontaneously switch positions to meet the club's needs. Calvin is the founder and leader of the club, with the official title of "dictator-for-life", while Hobbes is the club president, and second-in-command (first tiger). They frequently act as if there were many other members, usually cheering for them.
On at least two occasions, Hobbes suggested that Susie Derkins be allowed to join. Needless to say, Calvin vehemently disagreed with this.
At the beginning of each meeting, the last meeting's minutes are read aloud by Hobbes. These minutes are usually filled with name-calling and fighting. The reading of the minutes sometimes leads to even more fighting, until the meeting is over, and both Calvin and Hobbes are satisfied with the "progress" made.
Originally, Calvin and Hobbes planned to have their clubhouse in the garage, but after the catastrophe of "moving" the car out of the garage (which ended in the car rolling into a ditch), it was decided to have the clubhouse in Calvin's tree fort.
In one comic, Calvin and Hobbes had an emergency meeting in the "Box of Secrecy," a cardboard box, because Susie had to stay at Calvin's home for an afternoon, much to Calvin's dismay. This was also the last known G.R.O.S.S. meeting.
The Club Anthem
G.R.O.S.S. has an anthem, which starts with its refrain. The refrain starts as "Oh, GROSS, best club in the cosmos..." The rest of the refrain (or any other part of the anthem, for that matter) is unknown. It is sung at the end of meetings (singing it before it is scheduled is a punishable offense), and all members present must remove their hats while singing the refrain. Failure to do so results in punishment.
Use in story arcs
- The first story arc G.R.O.S.S. was involved in was when the two wanted to have their club headquartered in the garage. They push the car out of the garage, but it rolls down the driveway into the ravine across the street.
- In another, Calvin throws mushy apples at Susie after she hears the two arguing in the tree fort.
- Calvin planned an "ingenious" strategy of throwing a water balloon at Susie if she read a code deliberately dropped in front of her saying she would ruin all their "secret plans" if she went behind the house at noon. However, the plan backfired and Calvin ended up being sprayed with a hose by Susie.